Fusion of the midplane with the left intersectional plane: a liver anatomical variation revisited with multidetector-row CT.

This article updates the description of an anatomical variation of the liver, in which the gallbladder is adjacent to the ligamentum teres, that was described until now as "right-sided ligamentum teres and right umbilical portion of the portal vein". A study of eight patients showing this anatomical variation has led to a new archetypal anatomical description of the hepatic and portal veins, using multidetector-row computed tomography (MDCT) with three-dimensional (3D) volume-rendering (VR) reconstructions. While 2D axial imaging gave the same information, MDCT imaging with VR reconstructions provided a clear 3D visualization of this anatomical variation. Typical features can be described as follows: (1) juxtaposition of the ligamentum teres and the gallbladder; (2) typical portal vein branching with a right posterior branch, a left posterior branch and a main medial branch that terminates in the ligamentum teres; (3) two main hepatic veins and a hypotrophied medial hepatic vein. We think, based on the direct comparison of anatomical findings and knowledge of chronological embryological development, that this abnormality results from the defective development of the central part of the liver and not from the persistence of the right rather than the left umbilical vein. Because of the presence of only one medial plane, containing both the gallbladder and the ligamentum teres, we propose renaming it "fusion of hepatic planes".

Fusion of the planes of the liver: an anatomic entity merging the midplane and the left intersectional plane.

BACKGROUND: Alignment of the gallbladder fossa and the round ligament may be associated with an almost unknown portal vein branching anomaly. STUDY DESIGN: Ultrasonographic imaging allowed detection of this anomaly, which we characterized as fusion of the planes of the liver. When appropriate, additional specific radiologic examinations were performed (CT scanner supplemented with a three-dimensional reconstruction, a biliary cartography, or an angiography). Surgical consequences were studied from this series and from the literature. RESULTS: Seven patients (0.5%) had the following criteria: 1) round ligament, gallbladder fossa, and termination of the portal vein occurring in the same plane; 2) typical portal vein branching, including a right posterior branch, left branches, and a main medial branch terminated by the Rex's recessus; 3) two main hepatic veins without a significant middle hepatic vein; and 4) absence of the horizontal part of the left hepatic duct. Fusion of the planes may have been involved in two cases of iatrogenic bile duct injury and contraindicated a tumor resection and a right-liver donation. A review of the literature revealed that lack of recognition of the fusion of the planes led to a high proportion of surgical iatrogenic injury. Fusion of the planes could result from incomplete development of the central part of the liver, in agreement with embryologic knowledge. CONCLUSIONS: Knowledge of the fusion of the planes by hepato-biliary surgeons is important. This anomaly may lead to serious complications if it remains undetected during liver resection or bile duct surgery.

ABCB4 gene mutation-associated cholelithiasis in adults.

BACKGROUND & AIMS: We recently put forward arguments in favor of ABCB4 gene (adenosine triphosphate-binding cassette, subfamily B, member 4) defects as a risk factor for symptomatic cholelithiasis in adults. In this study, we characterized ABCB4 gene mutations in a series of patients with symptomatic cholelithiasis to determine the genetic basis and the clinical phenotype of ABCB4 gene mutation-associated cholelithiasis. METHODS: We analyzed the entire ABCB4 gene coding sequences in a first group of 32 patients who had a clinical history compatible with the syndrome previously described, in a second group of 28 patients who presented with a classic gallstone disease that justified a cholecystectomy, and in a third group of 33 patients without a history of cholelithiasis. RESULTS: We identified both heterozygous and homozygous ABCB4 gene point mutations in 18 of 32 (56%) patients who presented with clinical criteria of the syndrome, whereas no mutation was detected in the 2 other groups of patients (P < 0.001). Three independent clinical features were strongly associated with point mutations: recurrence of symptoms after cholecystectomy (odds ratio, 8.5); intrahepatic hyperechoic foci, intrahepatic sludge, or microlithiasis (odds ratio, 6.1); and age <40 years at the onset of symptoms (odds ratio, 3.0). ABCB4 gene point mutations were detected exclusively in the patients who showed 2 or 3 of these clinical features. CONCLUSIONS: Our results show that ABCB4 gene mutations represent a major genetic risk factor in a symptomatic and recurring form of cholelithiasis in young adults.

Variações anatômicas da veia porta intra-hepática estudo Ultra-sonográfico de 500 pacientes / Anatomic variations of the intra-hepatic portal vein - ultrasound study of 500 patients

Este estudo visou à análise ultra-sonográfica a disribuição anatômica do sistema intra-hepático e suas variações. Foram estudados, prospectivamente, 500 pacientes, no Seviço de Radiologia do Hospital Saint Antoine, em Paris. Foram encontrados, no total, cinco tipos de distribuição anatômica, sendo um, o mais frequente em 81 por cento dos casos, portanto considerado como habitual. Os quatro tipo restantes (19 por cento) foram: trifurcação da veia porta principal, ramo posterior direito nascendo direto da veia porta principal, ramo anterior direito nascendo da veia porta esquerda, e ausência do segmento horinzontal da veia porta esquerda. Os resultados obtidos foram bastante próximos daqueles encontrados na literatura. Em certas hepatectomias, o desconhecimento de dois tipos de distribuição anatômicas encontrados pode levar a complicações, até mesmo comprometendo parte ou a totalidade do parênquima hepático residual. Sendo o exame ultra-sinográfico capaz de detectar tais variações, o radiologista deve conhecê-las e analisá-las rotineiramente durante a realização dos exames, principalmente em casos de pré-operatório hepático.